Method of forming a semiconductor device by simultaneously cleaning both sides of a wafer using different cleaning solutions

Abstract

The present invention provides a method of removing a Cu-contamination from a wafer surface having a Cu-based metal region, comprising the step of: carrying out a cleaning process by use of a cleaning solution free of HF and capable of oxidation to the wafer surface for not only removing the Cu-contamination from the wafer surface but also oxidizing the wafer surface to cause the wafer surface to have a hydrophilicity.

What is claimed is:  
     
       1. A method of removing Cu-contamination from a wafer surface having a Cu-based metal region, comprising the steps of: 
       removing the Cu-contamination from a top surface of the wafer using a first cleaning solution; and  
       simultaneously applying a second cleaning solution to a bottom surface of the wafer for increasing the hydrophilicity of the bottom surface of the wafer to have a higher hydrophilicity than a substrate of the wafer.  
     
     
       2. The method as claimed in  claim 1 , wherein the first cleaning solution contains HF, and the second cleaning solution is free of HF and capable of oxidizing the wafer surface. 
     
     
       3. The method as claimed in  claim 2 , wherein the first cleaning solution contains a solution containing HF, H 2 O 2 , and H 2 O. 
     
     
       4. The method as claimed in  claim 2 , wherein the second cleaning solution contains one solution selected from the group consisting of ozonated water, water containing hydrogen peroxide, a solution containing HNO 3 , H 2 O 2  and H 2 O, a solution containing (HPM) HCl, H 2 O 2 , and H 2 O, a solution containing (SPM) H 2 SO 4 , H 2 O 2 , and H 2 O, a concentrated HNO 3  solution, a sulfuric acid solution dissolved with ozone, a nitric acid solution dissolved with ozone and a hydrochloric acid solution dissolved with ozone as well as a solution containing both hydrogen peroxide and sulfuric acid, a solution containing both hydrogen peroxide and nitric acid, and a solution containing both hydrogen peroxide and hydrochloric acid. 
     
     
       5. The method as claimed in  claim 1 , further comprising the steps of: 
       chemical mechanical polishing the wafer surface after said removing the Cu-contamination step; and  
       carrying out a post-cleaning process for removing an insulative contamination adhered on the wafer surface during the chemical mechanical polishing step.  
     
     
       6. The method as claimed in  claim 5 , wherein the post-cleaning process comprises the steps of: 
       subjecting the wafer surface to any one of a diluted ammonium solution, electrolyzed water processed through a cathode, and water containing dissolved hydrogen; and  
       subjecting the top surface of the wafer to an oxalic acid solution and the bottom surface of the wafer to at least one solution selected from the group consisting of a solution containing HF, H 2 O 2 , and H 2 O, and an oxalic acid solution.  
     
     
       7. A method of forming a semiconductor device comprising the steps of: 
       forming a Cu-based metal layer on a top surface of a wafer so that the Cu-based metal layer completely fills at least one groove formed in the top surface of the wafer;  
       carrying out a pre-cleaning process by use of a pre-cleaning solution free of HF and capable of oxidizing the wafer surface for not only removing Cu-contamination from a bottom surface of the wafer but also oxidizing the bottom surface of the wafer to cause the bottom surface of the wafer to be more hydrophilic than a substrate of the wafer;  
       annealing the wafer;  
       carrying out a chemical mechanical polishing for polishing the Cu-based metal layer to leave the Cu-based metal layer only within the at least one groove; and  
       carrying out a post-cleaning process by use of at least one post-cleaning solution for removing contaminations adhered on the wafer surface during the chemical mechanical polishing process,  
       wherein the Cu-based metal region is protected from the cleaning solution by injecting pure water to the Cu-based metal region.  
     
     
       8. A method of forming a semiconductor device comprising the steps of: 
       forming a Cu-based metal layer on a top surface of a wafer so that the Cu-based metal layer completely fills at least one groove formed in the top surface of the wafer;  
       carrying out a first pre-cleaning process for removing Cu-contamination from a top surface of the wafer using a first pre-cleaning solution;  
       simultaneously carrying out a second pre-cleaning process to the wafer surface using a second pre-cleaning solution for oxidizing the bottom surface of the wafer to cause the bottom surface of the wafer to be more hydrophilic than a substrate of the wafer;  
       annealing the wafer;  
       carrying out a chemical mechanical polishing for polishing the Cu-based metal layer to leave the Cu-based metal layer only within the at least one groove; and  
       carrying out a post-cleaning process using at least one post-cleaning solution for removing contaminations adhered on the wafer surface during the chemical mechanical polishing process.  
     
     
       9. The method as claimed in  claim 8 , wherein the first pre-cleaning solution contains HF, and the second pre-cleaning solution is free of HF and capable of oxidizing the wafer surface. 
     
     
       10. The method as claimed in  claim 9 , wherein the first pre-cleaning solution contains a solution containing HF, H 2 O 2 , and H 2 O. 
     
     
       11. The method as claimed in  claim 9 , wherein the second pre-cleaning solution contains a solution selected from the group consisting of ozonated water, water containing hydrogen peroxide, a solution containing HNO 3 , H 2 O 2  and H 2 O, a solution containing (HPM) HCl, H 2 O 2 , and H 2 O, a solution containing (SPM) H 2 SO 4 , H 2 O 2 , and H 2 O, a concentrated HNO 3  solution, a sulfuric acid solution dissolved with ozone, a nitric acid solution dissolved with ozone and a hydrochloric acid solution dissolved with ozone as well as a solution containing both hydrogen peroxide and sulfuric acid, a solution containing both hydrogen peroxide and nitric acid, and a solution containing both hydrogen peroxide and hydrochloric acid. 
     
     
       12. The method as claimed in  claim 8 , wherein the post-cleaning process comprises the steps of: 
       subjecting the wafer surface to any one of a diluted ammonium solution, electrolyzed water processed through a cathode, and water containing dissolved hydrogen; and  
       subjecting the top surface of the wafer to an oxalic acid solution and the bottom surface of the wafer to at least one solution selected from the group consisting of a solution containing HF, H 2 O 2 , and H 2 O, and an oxalic acid solution.  
     
     
       13. A method of removing Cu-contamination from a wafer surface having a Cu-based metal region, comprising the steps of: 
       removing the Cu-contamination from the wafer surface using a first cleaning solution;  
       applying a second cleaning solution to the wafer surface to increase the hydrophilicity of the wafer surface to have a higher hydrophilicity than a substrate of the wafer;  
       chemical mechanical polishing the wafer surface after said removing the Cu-contamination step; and  
       carrying out a post-cleaning process for removing an insulative contamination adhered on the wafer surface during the chemical mechanical polishing step,  
       wherein the post-cleaning process comprises the steps of:  
       subjecting the wafer surface to any one of a diluted ammonium solution, electrolyzed water processed through a cathode, and water containing-dissolved hydrogen; and  
       subjecting the top surface of the wafer to an oxalic acid solution and the bottom surface of the wafer to at least one solution selected from the group consisting of a solution containing HF, H 2 O 2 , and H 2 O, and an oxalic acid solution.